Provisional fixation pin

• US 5,968,046 A
• Filed: 06/04/1998
• Issued: 10/19/1999
• Est. Priority Date: 06/04/1998
• Status: Expired due to Term

• Current Assignee: Smith & Nephew Incorporated (Smith & Nephew PLC)
• Original Assignee: Smith & Nephew Incorporated (Smith & Nephew PLC)
• Inventors: Castleman, David
• Primary Examiner(s): Buiz, Michael
• Assistant Examiner(s): Shai, Daphna
• Application Number:
  US09/090,117
• Time in Patent Office: 502 Days
• Field of Search: 606/69, 606/70, 606/71, 606/73
• US Class Current: 606/286
• CPC Class Codes: A61B 17/80 Cortical plates , i.e. bone plates; Instruments for holding or positioning cortical plates, or for compressing bones attached to cortical plates
• CPC Class Codes: A61B 17/8605 Heads, i.e. proximal ends projecting from bone
• CPC Class Codes: A61B 17/8625 Shanks, i.e. parts contacting bone tissue

Abstract

A method and apparatus for reducing a fracture provides a provisional fixation pin to provisionally affix the bone plate to the bone prior to the installation of the bone plate with permanent attachment, such as bone screws. The method and apparatus of the present invention will maintain some reduction without significantly compromising the bone. The method utilizes a provisional fixation pin having an upper or proximal unthreaded shaft section and a lower externally threaded shaft section. A cutting tip is provided at the extreme distal end of the fixation pin. In between the proximal and distal sections is an enlarged diameter section that has an annular surface sized and shaped to conform to the countersunk surface of openings in the bone plate.

Claims

1. A method of reducing a patient'"'"'s fractured bone at a fracture site comprising the steps of:

a) preliminarily positioning a bone plate at the fracture site and at a selected provisional position, wherein the bone plate has a plurality of countersunk openings for receiving bone screws with countersunk head portions;

b) securing the bone plate to the patient'"'"'s bone tissue at the fracture site with a plurality of provisional fixation pins, each having a threaded distal portion that passes through a selected countersunk opening and into underlying bone tissue;

c) wherein the provisional fixation pins in step "b" each have an enlarged diameter portion that engages the countersunk opening of the bone plate;

d) using the plurality of provisional fixation pins to preliminarily hold the bone plate in the preliminary position of step "a"; and

e) permanently affixing the bone plate to the patient'"'"'s bone tissue at the provisional fixation site using bone screws that are implanted by placement through the countersunk openings of the bone plate, wherein each provisional fixation pin is removed and at least some of said provisional fixation pins are replaced with a bone screw.

5. A method of reducing a patient'"'"'s fractured bone at a fracture site comprising the steps of:

a) preliminarily positioning a bone plate at the fracture site and at a selected provisional position, wherein the bone plate has a plurality of countersunk openings for receiving bone screws with countersunk head portions;

b) securing the bone plate to the patient'"'"'s bone tissue at the fracture site with a plurality of provisional fixation pins, each having a threaded distal portion that passes through a selected countersunk opening and into underlying bone tissue;

c) wherein the provisional fixation pins in steep "b" each have an enlarged diameter portion shaped to fit the countersunk opening of the bone plate;

d) using the plurality of provisional fixation pins to preliminarily hold the bone plate in the preliminary position of step "a"; and

e) permanently affixing the bone plate to the patient'"'"'s bone tissue at the provisional fixation site using bone screws that are implanted by placement through the countersunk openings of the bone plate that are not occupied by provisional fixation pins;

f) the method of claim 1 wherein in step "c" the enlarged diameter portion has an annular surface that is shaped to fit the countersunk opening of the bone plate; and

g) wherein in step "c" the enlarged diameter portion has a domed annular proximal portion.

6. The method of claim 5, wherein the countersunk opening has a concave countersunk surface portion and further comprising the step of engaging the annular surface of the enlarged diameter portion with the countersunk surface portion.

7. The method of claim 6 wherein each countersunk opening includes a circular opening that is much larger in diameter than the threaded distal portion of the provisional fixation pins.

2. A method of reducing a patient'"'"'s fractured bone at a fracture site comprising the steps of:

a) preliminarily positioning a bone plate at the fracture site and at a selected provisional position, wherein the bone plate has a plurality of countersunk openings for receiving bone screws with countersunk head portions;

b) securing the bone plate to the patient'"'"'s bone tissue at the fracture site with a plurality of provisional fixation pins, each having a threaded distal portion that passes through a selected countersunk opening and into underlying bone tissue;

c) wherein the provisional fixation pins in step "b" each have an enlarged diameter portion shaped to fit the countersunk opening of the bone plate;

d) using the plurality of provisional fixation pins to preliminarily hold the bone plate in the preliminary position of step "a"; and

e) permanently affixing the bone plate to the patient'"'"'s bone tissue at the provisional fixation site using bone screws that are implanted by placement through the countersunk openings of the bone plate that are not occupied by provisional fixation pins,

f) wherein in step "e" a provisional fixation pin is removed from an opening in steps "d" and "e" before a bone screw is implanted in step "e".

3. A method of reducing a patient'"'"'s fractured bone at a fracture site comprising the steps of:

a) preliminarily positioning a bone plate at the fracture site and at a selected provisional position, wherein the bone plate has a plurality of countersunk openings for receiving bone screws with countersunk head portions;

b) securing the bone plate to the patient'"'"'s bone tissue at the fracture site with a plurality of provisional fixation pins, each having a threaded distal portion that passes through a selected countersunk opening and into underlying bone tissue;

c) wherein the provisional fixation pins in step "b" each have an enlarged diameter portion shaped to fit the countersunk opening of the bone plate;

d) using the plurality of provisional fixation pins to preliminarily hold the bone plate in the preliminary position of step "a"; and

e) permanently affixing the bone plate to the patient'"'"'s bone tissue at the provisional fixation site using bone screws that are implanted by placement through the countersunk openings of the bone plate that are not occupied by provisional fixation pins; and

f) wherein the provisional fixation pins have a lower end below the enlarged diameter portion that is much smaller in diameter than the bone screw of step "e", and further comprising the steps of removing a provisional pin from an opening and inserting a bone screw into the bone tissue opening that was formed in step "d".

4. A method of reducing a patient'"'"'s fractured bone at a fracture site comprising the steps of:

a) preliminarily positioning a bone plate at the fracture site and at a selected provisional position, wherein the bone plate has a plurality of countersunk openings for receiving bone screws with countersunk head portions;

b) securing the bone plate to the patient'"'"'s bone tissue at the fracture site with a plurality of provisional fixation pins, each having a threaded distal portion that passes through a selected countersunk opening and into underlying bone tissue;

c) wherein the provisional fixation pins in step "b" each have an enlarged diameter portion shaped to fit the countersunk opening of the bone plate;

d) using the plurality of provisional fixation pins to preliminarily hold the bone plate in the preliminary position of step "a"; and

e) permanently affixing the bone plate to the patient'"'"'s bone tissue at the provisional fixation site using bone screws that are implanted by placement through the countersunk openings of the bone plate, wherein each provisional fixation pin is removed and at least some of said provisional fixation pins are replaced with a bone screw;

f) wherein in step "c" the enlarged diameter portion has an annular surface that is shaped to fit the same countersunk openings of the bone plate that are receptive of the bone screws; and

g) wherein the enlarged diameter portion corresponds generally in size and shape to the countersunk head portions of the bone screws used in steps "a" and "e".

8. A bone plate apparatus for repairing a patient'"'"'s fractured bone at a fracture site comprising:

a) a bone plate having upper and lower surfaces and a plurality of countersunk openings through the plate, each opening including a countersunk surface that communicates with the upper surface of the plate;

b) a plurality of provisional bone pins that respectively fit the plurality of openings, each pin having a threaded lower section with a drilling tip, an upper section, and an enlarged diameter section in between the upper and lower sections;

c) the enlarged diameter section having a convex annular surface that closely conforms to the countersunk surface of an opening during use;

d) a plurality of bone screws that have a head and a threaded shank, wherein the diameter of the threaded shank is much larger than the diameter of the distal section of the provisional bone pin; and

e) wherein the head of each bone screw is about the same diameter as the enlarged diameter section of the provisional bone pin.

9. The bone plate apparatus of claim 8 wherein the diameter of the lower section of each provisional pin is about the same diameter as the diameter of the upper section.

10. The bone plate apparatus of claim 8 wherein the enlarged diameter section of one of said provisional bone pins is about the same size and shape as the head of one of said bone screws.

11. The bone plate apparatus of claim 8 wherein the provisional bone pin enlarged diameter section has a diameter that is many times greater than the diameter of the lower section.

12. The bone plate apparatus of claim 8 wherein the countersunk openings each include a concave countersunk surface that communicates with the upper bone plate surface and a generally circular opening that communicates with the lower bone plate surface.

13. The bone plate apparatus of claim 8 wherein the provisional bone pin distal section has a diameter of between 1 and 3 mm.

14. The bone plate apparatus of claim 8 wherein the provisional bone pin proximal section has a diameter of between 1 and 8 mm.

15. The bone plate apparatus of claim 8 wherein the enlarged diameter section has a diameter of between 4 and 10 mm.

16. The bone plate apparatus of claim 8 wherein the provisional bone pin distal section is externally threaded with a fine pitch thread pattern.

17. A method of reducing a patient'"'"'s fractured bone at a fracture site comprising the steps of:

a) preliminarily positioning a bone plate at the fracture site and at a selected provisional position, wherein the bone plate has a plurality of countersunk openings for receiving bone screws with countersunk head portions;

b) securing the bone plate to the patient'"'"'s bone tissue at the fracture site with a plurality of provisional fixation pins, each having a threaded distal portion that passes through a selected countersunk opening and into underlying bone tissue;

c) wherein the provisional fixation pins in step "b" each have an enlarged diameter portion shaped to fit the countersunk opening of the bone plate and a proximal section, wherein the enlarged diameter portion closely conforms to the countersunk surface of a bone screw receptive opening;

d) using the plurality of provisional fixation pins to preliminarily hold the bone plate in the preliminary position of step "a"; and

e) permanently affixing the bone plate to the patient'"'"'s bone tissue at the provisional fixation site using bone screws that are implanted by placement through the countersunk openings of the bone plate wherein each provisional fixation pin is removed and at least some of said provisional fixation pins are replaced with a bone screw.

18. The method of claim 17 wherein the provisional fixation pins have a lower end below the enlarged diameter portion that is much smaller in diameter than the bone screw of step "e", and further comprising the steps of removing a provisional pin from an opening and inserting a bone screw into the bone tissue opening that was formed in step "d".

19. The method of claim 17 wherein in step "c" the enlarged diameter portion has a lower annular surface that is shaped to fit the countersunk opening of the bone plate.

20. The method of claim 17 wherein in step "c" the enlarged diameter portion has a domed annular proximal portion.

21. The method of claim 17, wherein the countersunk opening has a concave countersunk surface portion and further comprising the step of engaging the lower annular surface of the enlarged diameter portion with the countersunk surface portion.

22. The method of claim 17 wherein each countersunk opening includes a circular opening that is much larger in diameter than the lower end portion of the provisional fixation pins.